In this procedure, you configure Thunderbird to encrypt and sign emails with the certificate from your smart card.
Before You Begin
You have completed How to Download Smart Card Certificates for Web and Email Use.
The green light should flash.
For CACKey, select /usr/lib/libcackey.so.
For Coolkey, select /usr/lib/libcoolkeypk11.so.
Thunderbird can now read the client certificates from your CAC card.
When composing the email message, pull down the Security menu and choose "S/MIME Sign" and "S/MIME Encrypt" before sending the message.